Numerous proposals to block the suns rays have been developed using opaque materials such as sheets of plastic and metal; where they are placed in front of the window aperture and drawn away from the line of sight, to fold or roll up.
A need to alternately have a window opaque, and then transparent has been considered imperative where shielding from all electromagnetic spectrum components when it has been inconvenient or infeasible due to constraints of use of space, or placement overhead, or under weightless conditions.
Accordingly there exists a need to combine space saving techniques, and ease of operation with variability of visual quality associated with its ability to go from opaque to translucent to transparent. The device of the present invention fulfills these several foregoing objectives.